1. Field of the Invention
The present invention is directed to a clutch arrangement for use in the drivetrain of a vehicle for the transmission of torque between a drive unit and a transmission, particularly an automatic transmission such as a multiple-speed automatic transmission or an automatic transmission with a continuously variable transmission ratio.
2. Related Art
In vehicles outfitted with an automatic transmission, the torque is generally transmitted between the drive unit and the transmission via a hydrodynamic torque converter. A hydrodynamic torque converter of this type can increase the torque delivered by a drive unit particularly in the starting state, i.e., in a state in which a lockup clutch of the converter is not engaged. At the same time, however, a hydrodynamic torque converter limits the speed that is possible in the starting state owing to its hydrodynamic characteristics. Due to the fact that modern drive units have comparatively high torques, i.e., torque conversion functionality is basically no longer required in the starting state, the torque limiting of a hydrodynamic torque converter in the starting state is perceived as problematic because it rules out sporty starting processes on the one hand and, on the other hand, makes it impossible to obtain higher outputs which can generally be achieved at higher rotational speeds. Further, hydrodynamic torque converters are comparatively complicated and costly systems owing to the hydrodynamic circuit contained therein and the components required for the hydrodynamic circuit, particularly the pump, turbine and stator.